"I will when I'm pressed and I'm challenged, or if they challenge my supporters," Paul continued, speaking Tuesday on CNN's American Morning. "Then I get annoyed and I feel offended when they do that, so I take that personally." Paul said he believes all his Republican rivals, including Cain, the former Godfather's Pizza executive, are qualified to be president.

Cain's plan "gives you a sales tax and a flat tax and opens the door to a value-added tax," Paul said. "I don't think it's going to tax those who have bigger incomes. It's a regressive tax. People are going to get a 9 percent sales tax and don't even have jobs right now? ... I think the more people know about it, the more questions will be asked."

Paul defended his own recently-unveiled economic plan, which he says will cut $1 trillion in spending by eliminating five federal departments and the Transportation Security Administration in addition to ending America's combat missions abroad. Paul would immediately eliminate the departments of Energy, Housing and Urban Development, Commerce, Interior, and Education. War spending would be terminated. Most other departments' spending would be capped at 2006 levels.

With his "No. 1 attack" on overseas spending, Paul said there are "enough places to cut" in the current budget that Medicare can be left alone. "We don't need to attack the elderly," he said. "We have made promises. That was a contract, even though it's not the best program in the world... I think if we cut elsewhere we don't have to put people on the streets." Paul said his plan does address Social Security by letting "young people opt out."
The libertarian candidate, who has long advocated for smaller government, said he isn't making changes to his strategy in Tuesday's debate. "I'm going to do exactly what I've been doing for as long as I can remember," he said.